The world’s deep seafloors are dark and airless places, but vast swaths may pulse gently with energy conducted through a type of newly discovered bacteria that forms living electrical cables.The bacteria were first detected in 2010 by researchers perplexed at chemical fluctuations in sediments from the bottom of Aarhus Bay in Denmark. Almost instantaneously linking changing oxygen levels in water with reactions in mud nearly an inch below, the fluctuations occurred too fast to be explained by chemistry.
Only an electrical signal made sense — but no known bacteria could transmit electricity across such comparatively vast distances. Were bacteria the size of humans, the signals would be making a journey 12 miles long.
Now the mysterious bacteria have been identified. They belong to a microbial family called Desulfobulbaceae, though they share just 92 percent of their genes with any previously known member of that family. They deserve to be considered a new genus, the study of which could open a new scientific frontier for understanding the interface of biology, geology and chemistry across the undersea world.
The bacteria are described Oct. 24 in Nature by researchers led by microbiologists Christian Pfeffer, Nils Risgaard-Petersen and Lars Peter Nielsen of Aarhus University. On the following pages, Wired takes a look at these marvelous microbes.
Seen through an electron microscope, the Desulfobulbaceae — the researchers haven’t yet given them a genus or species name — appear in blue. They link end-to-end, forming filaments nearly an inch in length. Image: Nils Risgaard-Petersen
Citations: “Filamentous bacteria transport electrons over centimetre distances.” Christian Pfeffer, Steffen Larsen, Jie Song, Mingdong Dong, Flemming Besenbacher, Rikke Louise Meyer, Kasper Urup Kjeldsen, Lars Schreiber, Yuri A. Gorby, Mohamed Y. El-Naggar, Kar Man Leung, Andreas Schramm, Nils Risgaard-Petersen & Lars Peter Nielsen. Nature, Vol. 490, No. 7421, 25 Oct. 2012
“Bacterial power cords.” By Gemma Reguera. Nature, Vol. 490, No. 7421, 25 Oct. 2012